Lack of detectable equine herpesviruses 1 and 2 in paraffin-embedded specimens of equine sarcoidosis.

BACKGROUND: Equine sarcoidosis is a rare, multisystemic, noncaseating, granulomatous and lymphoplasmacytic disease of unknown etiology. A recent report described a horse with granulomatous skin disease displaying histologic, electron microscopic, and polymerase chain reaction (PCR) findings consistent with equine herpesvirus 2 (EHV-2). OBJECTIVE: To investigate the presence of EHV-2 and equine herpesvirus 1 (EHV-1) in 8 horses with sarcoidosis. ANIMALS: Eight horses with sarcoidosis, reported previously. METHODS: Retrospective study. PCR assays of the tissues were performed to detect DNA associated with EHV-1 and EHV-2. For both herpesviruses the target was their respective glycoprotein B gene. Positive controls consisted of DNA from viral cultures of culturettes from naturally occurring respiratory infections of EHV-1 and EHV-2. RESULTS: The PCR analyses for both equine herpesviruses' DNA were negative in all 8 horses. CONCLUSION: The failure to detect DNA from EHV-1 and EHV-2 in paraffin-embedded skin of these 8 horses does not discount EHV-1 or EHV-2 as causing some cases of ES, but lends support to the presumably multifactorial etiologic nature of the disease.

The longevity of immunoglobulin preservation in canine skin utilizing Michel's fixative.

Skin biopsy specimens from 7 dogs with immune-mediated skin diseases diagnosed by routine histology and 5 dogs with other skin diseases were placed in Michel's transport medium for 4 to 9 years. Direct immunofluorescence yielded positive results in tissue samples from 3 dogs with pemphigus foliaceus and 2 dogs with discoid lupus erythematosus. Direct immunofluorescence was not seen in tissue samples from 1 dog with pemphigus foliaceus and 5 dogs with non immune-mediated skin diseases. Direct immunofluorescence was seen in skin biopsy specimens maintained in Michel's medium for 4 to 8 years.

Canine discoid lupus erythematosus.

Two dogs were found to have clinical, histopathological and immunofluorescent findings compatible with a diagnosis of canine discoid lupus erythematosus. The primary lesions included erythema and depigmentation of the nasal planum. Both dogs responded favorably to systemic corticosteroid therapy.

Thiopurine methyltransferase in red blood cells of dogs, cats, and horses.

Our objective was to determine if thiopurine methyltransferase (TPMT), the enzyme important in the metabolism of azathioprine in human beings, is detectable in red blood cell lysates (RBCL) of healthy dogs, cats, and horses. Values for TPMT activity were determined from blood collected from 20 healthy dogs, cats, and horses. The TPMT activity in each animal's RBCL was determined using a radioenzymatic end point involving TPMT-facilitated metabolism of 6-mercaptopurine to 6-methylmercaptopurine (6-MMP). One unit of TPMT activity represents the formation of 1 nmol of 6-MMP per milliliter of packed red blood cells per hour of incubation at 37 degrees C. TPMT activity in RBCL was detectable in all species, with mean RBC values +/- standard deviation of 17.9 +/- 3.79 U/mL in dogs; 2.76 +/- 0.70 U/mL in cats; and 2.185 +/- 0.36 U/mL in horses. Values for TPMT in the 3 species were significantly (P < .05) different from one another. TPMT values for dogs were significantly higher than the other species, and TPMT values for cats were significantly higher than those for horses. We conclude that RBCL TPMT values are measurable in dogs. cats, and horses and that dogs have higher values than cats or horses. These findings are consistent with the lower tolerance for azathioprine in cats as compared with dogs. It remains to be determined whether RBCL TPMT values in these species correlate with TPMT activity in the liver, where most of the metabolization of azathioprine is believed to occur.

Circulating immune complex concentrations in selected cases of skin disease in dogs.

Serum samples from 25 clinically normal dogs and 137 base-line serum samples from dogs with skin disease were assayed blindly for presence of circulating immune complexes (CIC). The method used was a solid-phase C1q-binding enzyme-linked immunosorbent assay. This assay detected only IgG-containing CIC that were capable of binding C1q. Statistical analysis revealed that dogs with systemic lupus erythematosus, discoid lupus erythematosus, generalized demodicosis, and recurrent staphylococcal pyoderma had significantly higher mean CIC concentrations than did normal dogs. Dogs with other skin diseases had mean CIC concentrations indistinguishable from those of normal dogs. Presence of CIC in dogs with these dermatopathies may have pathogenetic significance or may be the result of the disease process. Further studies are necessary to define the antigens contained in the immune complexes and the importance of CIC in skin disease of dogs.

Effects of hormonal therapy on the microbiology of seborrheic dogs.

Quantitative and qualitative bacterial assays were performed on the skin of three dogs with endocrine-related primary metabolic seborrhea. After the dogs were treated (thyroid supplementation or castration, bacterial analyses were again performed on the same sites. Before therapy, the dogs had a cutaneous flora composed mainly of Staphylococcus aureus coagulase-positive organisms. After therapy, there was a significantly lower bacterial count, and two of the dogs had floras consisting mainly of coagulase-negative cocci. During the study, the two dogs that reverted bacteriologically to a normal cutaneous microenvironment became normal dermatologically. The third dog improved, but continued to have minor signs of seborrhea.

Cutaneous fungal flora in twenty horses free of skin or ocular disease.

The fungal flora of the hair and underlying skin from 2 sites was examined qualitatively in 20 horses free of skin or ocular disease. Fungi were isolated from both the hair and the underlying skin of all 20 horses. Twenty-two genera regarded commonly as saprophytes were identified and an additional 2 fungi resembled the perfect state of the cutaneous pathogenic genera Microsporum and Trichophyton. Cladosporium spp, Penicillium spp, and Rhizopus spp were the most frequently isolated saprophytes. In general, similar fungi were isolated from the hair and underlying skin, and differences were not noted in isolates from the saddle and rump regions.

Microbiology of normal and seborrheic canine skin.

Quantitative and qualitative bacterial assays were performed on the skin of 15 normal and 32 seborrheic dogs. Nonionic detergent scrubs were made on areas demarcated by glass sidearm cylinders. Quantitative analysis was accomplished by the serial dilution technique, and the bacteria were identified by individual and colonial morphology and by enzyme production. Areas measured on control dogs had a markedly lower total bacterial count than similar areas measured on seborrheic animals. Control dogs had a flora consisting primarily of coagulase-negative cocci, whereas seborrheic dogs usually had a cutaneous flora composed primarily of Stahylococcus aureus, coagulase-positive.

Determination of skin concentrations of enrofloxacin in dogs with pyoderma.

OBJECTIVE: To compare serum and skin concentrations of enrofloxacin in dogs with pyoderma with those of clinically normal dogs and to evaluate concentrations in dogs with superficial versus deep pyoderma. ANIMALS: 16 clinically normal dogs and 16 dogs with pyoderma. PROCEDURE: Enrofloxacin (approx 5 mg/kg of body weight, PO) was administered daily to all dogs. Serum samples and skin biopsy specimens were obtained on day 1 at 3 hours after drug administration and on day 3 immediately before and 3 hours after drug administration. Samples and specimens were assayed by high-performance liquid chromatography. Morphometric analysis was performed on skin biopsy specimens to determine correlation between inflammatory cells and peak tissue enrofloxacin concentration on day 1. RESULTS: Morphometric analysis revealed high correlation between dermal inflammatory cell count and drug concentration in dogs with pyoderma. CONCLUSIONS: At mean dosage of 5 mg/kg once daily, enrofloxacin tissue concentrations were significantly greater in dogs with pyoderma at 3 hours after pill administration. Enrofloxacin tissue concentration on day 3 at 3 hours after pill administration was 12.4 times the 90% minimum inhibitory concentration of enrofloxacin for Staphylococcus intermedius. CLINICAL RELEVANCE: In dogs with pyoderma, therapeutic tissue concentrations of enrofloxacin are reached as early as 3 hours after drug administration.

Vitamin A-responsive dermatosis in the dog.

In 3 dogs, focal, well-circumscribed skin lesions compatible clinically with seborrheic dermatitis responded to oral treatment with vitamin A. Skin biopsy findings were compatible with phrynoderma in man, a disease thought to be associated with vitamin A deficiency. The dogs had been fed commercial dog food and were otherwise healthy. The skin lesions resolved rapidly and completely with vitamin A therapy. Seven other dogs with similar lesions but with histopathologic findings not compatible with phrynoderma or follicular keratosis did not respond to vitamin A therapy.

Grass awn migration in dogs and cats: a retrospective study of 182 cases.

A retrospective study of 182 cases of grass awn migration in dogs and cats seen during a 1-year period was performed. The 182 cases comprised 61% of all foreign body-related cases during that year. Compared with the total hospital population, there was an increased prevalence of grass awn problems in the Springer Spaniel, Golden Retriever, Brittany Spaniel, and Airedale Terrier, but a decreased prevalence in German Shepherd Dogs, Miniature Poodles, and Dachshunds. The most common site of grass awn localization was the external ear canal, involving 51% of grass awn cases. Other common sites of grass awn localization included the interdigital webs, eye, nose, lumbar area, and thoracic cavity. Only 8 of the 182 animals were cats and 7 of the 8 had ocular involvement.

Regional distribution of ten common skin diseases in dogs.

We investigated the regional distributions of the most commonly diagnosed skin diseases in dogs from 17 North American veterinary teaching hospitals. Between January 1983 and December 1983, 11,456 diagnoses of skin disease were made. The 10 most common diagnoses were fleabite allergic dermatitis, skin cancer, pyoderma, seborrhea, allergy, demodectic acariasis (demodicosis), sarcoptic acariasis, immune-mediated skin disease, endocrine related skin disease, and acral lick dermatitis. Regional differences in the frequency of skin diseases were apparent. The northeast region had high frequencies of fleabite allergic dermatitis, allergy, and immune-mediated disease, and a low frequency of seborrhea. The midwest had a high frequency of seborrhea, and low frequencies of demodectic acariasis and allergy. In the plains region, low frequencies of fleabite allergic dermatitis, pyoderma, seborrhea, allergy, and demodectic acariasis were detected. In the west, the frequencies of fleabite allergic dermatitis, skin cancer, pyoderma, seborrhea, and acral lick dermatitis were high, whereas few dogs had allergic disease and sarcoptic acariasis. The southwest had high frequencies of fleabite allergic dermatitis and demodectic and sarcoptic acariasis. Fleabite allergic dermatitis, pyoderma, and demodectic and sarcoptic acariasis were frequently diagnosed in the southeast, but the number of dogs with seborrhea was low.

Pemphigus foliaceus in dogs: a review of 37 cases.

Thirty-seven dogs with pemphigus foliaceus were seen over a span of 9 years in a veterinary medical teaching hospital. Four breeds of dogs (Bearded Collie, Akita, Newfoundland, Schipperke) were at significant elevated risk when compared with both the dermatology canine case population and the hospital canine population. The mean age of onset was 4.2 years. The dorsal part of the muzzle was the most common site of initial involvement in over 50% of the dogs, and lesions of the head were seen first in 81% of the dogs. Disease progression was gradual (greater than 3 months) in 73% of the dogs. Somewhat bilaterally symmetric scaling, crusting, and alopecia were seen in all of the dogs. Vesicles, pustules, and bullae were not seen commonly, but target lesions with peripheral collarettes were seen frequently. Most dogs had characteristic footpad lesions, with erythematous swelling at the pad margins, cracking, and villous hypertrophy. Generalized exfoliative dermatitis was seen in dogs with widespread disease. Pruritus was noted in less than one half of the dogs. Typical histopathologic findings included subcorneal and intragranular cell layer epidermal pustules, or intrafollicular pustules with prominent acantholysis. Direct immunofluorescence in an intercellular pattern was noted in 76% of the dogs tested and indirect immunofluorescence was noted in 75% of a much smaller sample. Thirty-nine percent of the dogs responded to corticosteroid therapy alone, and 50% and 55% responded, respectively, to prednisone and cytotoxic drugs, and to prednisone with aurothioglucose. Aurothioglucose was successful alone in 27% of the dogs. One-year survival was achieved in 53% of the dogs.

Urinary tract infection associated with long-term corticosteroid administration in dogs with chronic skin diseases.

Urinary tract infections were documented in 28 (39%) of 71 dogs receiving long-term corticosteroid therapy for chronic skin diseases. There were no significant differences regarding alternate-day versus daily corticosteroid administration, corticosteroid dosage, or duration of therapy when data for the infected and noninfected groups were compared. A significantly (P less than 0.01 and P less than 0.005, respectively) greater frequency of bacteriuria was seen in female dogs and castrated male dogs receiving corticosteroid therapy. Urine sediment analysis alone was not an adequate means of detecting urinary tract infections in these dogs.

Pemphigus foliaceus of the footpads in three dogs.

Severe hyperkeratinization and villous hypertrophy of the footpads were seen in 3 middle-aged dogs. Peeling, fissuring, swelling, and ulcerations were noted on the margins of severely affected pads. Pain was evident in palpation and ambulation. Lesions were compatible with the traditional diagnosis of "hard pad disease". Histopathologic findings were diagnostic for canine pemphigus foliaceus in all 3 dogs, and direct immunofluorescence in an intercellular pattern was seen in both dogs that were tested. All 3 dogs responded to immunosuppressive dosages of corticosteroids.

Histopathologic features of pyotraumatic dermatitis.

The skin of 17 dogs with pyotraumatic dermatitis was studied microscopically. Two patterns were seen. The first pattern was a superficial, ulcerative, inflammatory process of undetermined cause and pathogenesis. Current recommended treatment, which includes corticosteroids, was believed to be appropriate for such lesions. The second pattern, suppurative folliculitis, was considered to be localized pyoderma. Dogs with severe folliculitis were believed to represent those cases of pyotraumatic dermatitis in which the response to corticosteroid treatment has been poor. It was concluded that antibiotics should be used for treating pyotraumatic dermatitis with suppurative folliculitis, in lesions responding poorly to treatment with corticosteroids, or possibly in any severe lesion of pyotraumatic dermatitis, especially in Golden Retrievers and Saint Bernards.

Dermatosis associated with feeding generic dog food: 13 cases (1981-1982).

The records of 13 dogs with a crusting dermatosis of the mucocutaneous junctions, pressure points, and trunk were evaluated. All of the dogs had been fed corn- and wheat-based commercial dry dog foods that failed to meet the National Research Council's recommendations for balanced nutrition. The dermatosis in all 13 dogs resolved completely after the diet was changed to one that met the National Research Council's recommendations. The disease was similar to that which has previously been called canine dry pyoderma, but is now known to be a zinc-responsive dermatosis.

Use of etretinate for treatment of primary keratinization disorders (idiopathic seborrhea) in cocker spaniels, west highland white terriers, and basset hounds.

An open clinical trial was used to evaluate the synthetic retinoid, etretinate, for treatment of idiopathic seborrhea in Cocker Spaniels, West Highland White Terriers, and Basset Hounds. Clinical and histologic improvement was seen in the Cocker Spaniels. Etretinate had no beneficial effect on the skin disease of the West Highland White Terriers or the Basset Hounds. Etretinate treatment did not alter the type or degree of otitis externa. Clinical side effects were minimal. Relevant laboratory abnormalities were not detected.

Dapsone for treatment of pruritic dermatitis (dermatitis herpetiformis and subcorneal pustular dermatosis) in dogs.

Pruritic dermatitis in 4 dogs was not responsive to treatment with corticosteroids and antibiotics. Histologic findings in 3 cases were suggestive of subcorneal pustular dermatosis, and those in the 4th case were compatible with dermatitis herpetiformis. All 4 dogs responded rapidly and completely to treatment with dapsone.

Cutaneous atypical mycobacteriosis in cats.

Cutaneous infection with atypical mycobacteria was observed in 6 cats. All cats had cutaneous or subcutaneous masses, with or without fistulous tracts. Diagnosis was determined by microbial culture. Transmission studies were done in 1 case. Treatment, which included antibiotics or surgery, or both, was usually unsuccessful, but remission without treatment did occur. In 3 cats available for long-term evaluation, there has been no recurrence of disease.